In storages using a flash memory, a high-speed PCI-Express (PCIe) is increasingly employed as a host interface. As a storage-side protocol of PCIe connection, NVM-Express (NVMe), and the like have appeared.
In a system in which a host device and a storage device are connected by the PCIe, a command, data, and a pointer pointing to a location of the data are placed in a memory inside the host device. A data region is fixed to have a predetermined size, and a pointer exists with respect to each data region. Therefore, the number of pointers is increased as the data size becomes larger.
The storage device needs to acquire pointers from the host device in order to execute a command. If the storage device tries acquiring all of pointers corresponding to a command, execution of which is instructed, a memory capacity therefor is increased.